In the related art, a DIN (German Institute for Standardization) abrasion tester and a Williams abrasion tester are known testers for evaluating the wear resistance of rubber. These testers perform a test basically on one rubber sample at a time. Thus, to obtain test results from a plurality of rubber samples, sufficient time is needed or a plurality of testers are needed.
An example of a device that simultaneously tests a plurality of rubber samples is a testing device in which a plurality of rubber samples (test pieces) are attached to a first shaft and a plurality of counterpart pieces are attached to a second shaft (see Japan Utility Model Patent No. 3003469). This testing device has a structure whereby the opposing rubber samples and the counterpart pieces are pressed together at a predetermined pressing force by a pressing device and are rotationally driven while running against one another to wear the rubber samples.
However, this testing device has a structure whereby the rubber samples are pressed against the counterpart pieces as a group and not individually. Thus, when rubber samples having a different amount of wear per unit time are simultaneously tested, the pressing force against the relatively easily worn rubber sample is reduced. This prevents an accurate determination of the relative wear resistance of the rubber samples, and thus there is room for enhancement.